The present invention relates to an ion source for a mass spectrometer and a method of ionising a sample. The preferred embodiment relates to a mass spectrometer and a method of mass spectrometry.
A known impactor spray Atmospheric Pressure Ionisation (“API”) ion source is disclosed in WO2012/143737 (Micromass). According to the known ion source an analyte is dissolved in solution and is introduced to a nebuliser. The heated high velocity liquid spray which is emitted from the nebuliser is arranged to impact upon a relatively small cylindrical rod target that is held at a high electrical potential with respect to the potential of the nebuliser. The resulting plume from the target is then sampled into a mass spectrometer for subsequent mass analysis. Information relating to the analyte such as the mass to charge ratio of analyte ion can be determined from the analysis.
It is also known to separate the analyte solution in a liquid chromatographic column prior to its introduction into the nebuliser. This allows additional chromatographic information relating to the analyte to be determined.
Other commercially available ambient Atmospheric Pressure Ionisation (“API”) ion sources include Desorption Electrospray (“DESI”) ion sources (see, for example, WO2005/094389 (Takáts)) and Direct Analysis in Real Time (“DART”) ion sources.
It is desired to provide an improved ion source for a mass spectrometer.